BackgroundAs autoimmune phenomena following anti-nSARS-CoV2 vaccine was reported in the healthy population, there is increasing concern in patients with inflammatory joint diseases regarding possible side effects and disease flare-ups.ObjectivesWe set out to evaluate the possible risk of disease exacerbation and the predisposing risk factors for the flare up.MethodsThis is a single center prospective cohort study, enrolling patients attending Arthritis Clinic at San Bortolo Hospital, during a follow-up of 12 months. All patients, after obtaining informed consent, answered a 24-item questionnaire including information about nSARS-CoV2 infection, vaccination, disease activity, ongoing treatment, vaccine side effects, disease flare up and need to change therapy.ResultsA total of 109 patients, 60 (55.1%) females and 49 (44.9%) males with a mean age of 60.1 years ±12.6 SD were enrolled. Forty-three (39.5%) were affected by rheumatoid arthritis, 43 (39.5%) from psoriatic arthritis and 23 from anchylosing spondylitis. There were 19 (17.43%) nSARS-CoV2 infection, of them 3 (15.8%) need hospitalization. Ninety-five (87.2%) receive at least one shot of nSARS-CoV2 vaccine, of these 78 (82.1%) got three shots of vaccine. Vaccine-related side effects were reported in 36 (37.9%), of these 15 (41.7%) have fever, 14 (38.8%) arthralgia and 29 (80.5%) fatigue. No patients required medical attention. Twenty (21.05%) of patients who receive at least one vaccine shot experienced a flare up. Nine (45%) need to change therapy. The risk of flare up was significantly associated with low disease activity/active disease in the last 12 months, p=0.009; OD 4.0; 95% CI: 1.5-11.3.ConclusionOverall, the nSARS-CoV2 vaccine is well tolerated in patients with inflammatory arthritis. The risk of disease flare is associated with active disease within the past 12 months. According to our results, the patients affected by inflammatory arthritis in sustained remission have no reason to hesitate to get the nSARS-CoV2 vaccination.Disclosure of InterestsNone declared